1. Field of the Invention
The present invention relates to an optical lens system, and more particularly, to a compact optical lens system used in electronic products.
2. Description of the Prior Art
The demand for compact imaging lens assembly has grown in recent years as the popularity of portable electronic products with the photographing function has increased. The sensor of a general photographing camera is none other than CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor Sensor). Furthermore, as advanced semiconductor manufacturing technology has allowed the pixel size of sensors to be reduced, and the current electronic products are leaning toward a trend of being more compact, there is an increasing demand for compact imaging lens assembly featuring better image quality.
A conventional imaging lens system with high resolving power, such as the one set forth in U.S. Pat. No. 7,365,920, generally has a front stop and four lens elements; wherein, the first and second lens elements are adhered together to form a doublet for correcting the chromatic aberration. However, this kind of arrangement has the following disadvantages. First, the degree of freedom in arranging the lens system is curtailed due to the employment of excessive number of spherical glass lenses; thus, the total track length of the system cannot be reduced easily. Second, the process of adhering glass lenses together is complicated, posing difficulties in manufacturing.
Besides, although the four-lens system disclosed in U.S. Pat. No. 7,848,032 does not have the aforesaid disadvantages, the system fails to be well-designed for infrared band. In considering the current situation that applications of lens systems capable are getting more and more, the conventional four-lens systems designed can no longer satisfy the current demands in the field.
In light of foregoing, there is a need for a compact lens system with excellent image quality and sensing susceptibility for portable electronic products, which can be applied for various applications.